<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
   // Symbol 作为属性名，该属性不会出现在for...in、for...of循环中
    let obj ={
        name:"damu",
        age:18
    };
    let symbol = Symbol("a");
    obj[symbol] ="a";

    console.log(obj)
    for(item in obj){
        console.log(item)
    }
</script>
</html>